Steam-powered spray iron

ABSTRACT

THE INVENTION DISCLOSES A STEAM-POWERED SPRAY IRON WHICH USES A PRESSURE REGULATING VALVE BETWEEN THE WATER TANK AND STEAM GENERATOR FOR MAINTAINING A SUBSTANTIALLY UNIFORM STEAM PRESSURE IN THE GENERATOR FOR OPERATING THE SPRAY. THE PRESSURE REGULATING VALVE IS IMPROVED TO INCREASED RELIABILITY, TO REDUCE THE NUMBER OF PARTS, THE OVERALL HEIGHT, AND THE COST OF THE IRON.

Sept. 2l, 1971 w E, DAvlDSON EI'AL 3,606,591

STEAK-POWERED SPRAY IRON Filed June 18, 1970 Q vidson, Kay' Tofu lfw www

William E. Da

United States Patent O Inf. Cl. Dosf 75/06 U.S. Cl. 38-77.5 9 ClaimsABSTRACT OF THE DISCLOSURE The invention discloses a steam-powered sprayiron which uses a pressure regulating valve between the water tank andsteam generator for maintaining a substantially uniform steam pressurein the generator for operating the spray. The pressure regulating valveis improved to increased reliability, to reduce the number of parts, theoverall height, and the cost of the iron.

BACKGROUND OF THE INVENTION (l) Field of the invention The inventionherein pertains to a steam-powered spray iron and, more particularly, toa spray/steam iron which employs a novel pressure regulating valve tocontrol 'the steam pressure for reliably operating the spray and reducethe number of parts and overall height of the structure to improveoperation and reduce the cost of the iron.

This application is a continuation-in-part of my application Ser. No.23,884, filed Mar. 30, 1970, assigned to the same assignee and nowabandoned.

(2) Description of the prior art With the advent of irons using waterfor either steam or spray purposes or both, it is customary to provide aWater tank in the iron above the soleplate and to use water valvestructures -to provide controlled Water drippage into a steam boiler orgenerator where it is evaporated and directed out apertures in thesoleplate to steam the article. Additionally, powered spray attachments,either steam r manual, have been added to such irons to supply a finespray from the water tank to spray onto the garment. The powered sprayform uses continuous steam pressure to assist in expelling an atomizedmixture of water and steam from the sprayer. In such a spray, a singledepression of the operating button provides a continuous spray. Insteam-powered spray irons it is necessary to have a pressure control orregulating valve to maintain a specific pressure Within the steamgenerating system to generate and power the spray. Some irons have aclosed steam system which generates steam at a relatively constant rateso in order to maintain a constant pressure in the closed system it isnecessary to bleed excess steam through a control valve. When the ironis used for spraying, most of the steam generated is used thus theamount of steam bleed through the pressure control or regulating valveis relatively low. On the other hand, when the iron is being used as asteam iron, the amount of steam bleed is identical to the amountproduced thus it is necessary to have a pressure control device whichwill regulate or bleed various amounts of steam at a near constantpressure. This generally has involved a valve to maintain the pressurein the closed system substantially constant. A typical power spray isshown in U.S. Pat. 3,041,757 of common assignment. As seen there, thepressure regulating valve has generally involved a valve stem thatextends up into the iron and is spring biased lto closed position in vaknown manner.

3,606,691 Patented Sept. 21, 1971 SUMMARY OF THE INVENTION Brieydescribed, the present invention is directed to a steam-powered sprayiron that has a steam generator and a closed water tank above thegenerator with means to pass water from the tank to the generator. Meansis also provided to ensure pressure communication between the generatorand the tank. A steam discharge passage provides a sole outlet for steamfrom the generator during normal ironing operation. In this environment,the invention discloses an improvement in the pressure regulating valvelocated in the steam discharge passage and used to maintain asubstantially uniform operating pressure in the generator and tank. Theimproved valve provides a helical-coiled spring that is seated in asealing relation in a cover over the steam generating cavity. The springis prestressed into a closed or unstretched position and is preferablytapered or coned in a downstream direction away from the tank. A checkvalve such as ball means is disposed within the spring and is operativeto permit unrestricted flow through the spring upstream towards thegenerator when the pressure in the generator is equal to or lower thanambient and the check valve means blocks reverse ow to thus unstress thespring to stretch it and permit flow through the passage and the springconvolutions in a downstream direction to then be distributed when thegenerator pressure is equal to or greater than ambient plus theprestressed value. Suitable screen means m'ay be secured over the top ofthe spring in the cover. Thus, the main object of the invention is toprovide a powered spray iron with an improved pressure regulator thatuses fewer parts, reduces the valve height, simplies construction, andreduces the cost of the iron.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is an elevational view,partially in section and broken away, showing general parts of an ironand illustrating a preferred form of the invention;

FIG. 2 is an enlarged partial sectional view of the detailed pressureregulating valve shown in FIG. l;

FIG. 3 is a modified form of valve;

FIG. 4 is a perspective exploded View of the parts of pressureregulating valve showing another modification; and

FIG. 5 is a graph of the operating characteristics of the valve as usedin an iron.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. l, thereis shown an electric steam-powered spray iron which includes a soleplate10 having a plurality of steam ports or apertures 12 and an outer shell14 connected in any suitable manner to handle 1'6 all in known fashion.In accordance with conventional practice, soleplate 10 may be cast froma suitable material, such as aluminum, with an electrical heatingelement |18 cast in position. This heating element preferably is of thesheathed type and, with the electrical resistance element, extendsthrough an outer tubular protective sheath and is separated from theouter sheath by an insulating compound resistant to heat such asgranulated and compressed magnesium oxide. The heating element generallyextends in a loop beginning at the rear of the iron and along one sideto the forward end then rear-wardly along the other side. Thus,substantially uniform heat distribution is provided when the iron isplugged in and activated.

The iron includes means for generating steam by providing water tank 20which may have a vertical outer tube means 22 in the forward portion forhousing various operating mechanisms. For steam, soleplate has a steamboiler or generator cavity 24 that is under control of a wate'r valvestructure generally indicated at 25 and including a button 26 withconnected spring-biased vertical stem 28 which is preferably located intube 22. Water may be dripped through orifice 29 from tank 20 onto theheated soleplate, the resulting steam being eventually distributedthrough passages 30 under chamber cover 32 and out ports 12 onto thefabric being ironed. The steam-powered spray attachment generallyindicated at 34 may be operated by control button 36 through connectedlinkage as is well-known. A typical power spray is shown in U.S. Pat.3,041,757 of common assignment. Temperature control 38 operates tothermostatically control the heat generated in the soleplate in a knownmanner. For supplying water to the tank for steam and spray power, -tillopening 40 is provided with direct communication to the tank.

In order for the water in tank 20 to be able to drip through orice 29and through the chamber cover into steam generator 24 when water valve25 is in the up or on-position, it is necessary, in the closed system,to equalize the steam pressure in generator 24 and water tank 20 and, tothis end, it is customary to provide a pressure balancing means intheform of a vertical balance tube 42 that is open at its upper end to theupper portion of tank 20 and open at its bottom end to generator 24 asshown in FIG. 1. Thus, the steam pressure is equalized on both sides ofwater valve so water will drip at a constant rate for steam generation.The balance tube may be mounted on a steam dome 44 that has open accessto generator 24 and is secured to cover 32. For controlling steampressure in the closed system, a suitable steam regulating valve ofgenerally known construction per se is provided as shown in FIG. 3 ofthe referenced 3,041,757 patent. This has generally included arelatively high separate openended tube means that has been mounted onthe steam dome 44 adjacent balance tube 42. Thus, steam from generator24 passes directly down through the cover onto the soleplate when thesteam pressure opens the regulating valve, generally indicated at `46,and which is located in discharge passage 47 as the sole outlet from theiron for steam during normal ironing operation. The steam may also passdirectly up balance tube 42 `where it subsequently powers spray 34 in aknown manner.

In accordance with the invention, discharge passage 47 houses pressureregulating valve 46 that has been greatly simplified and reduced ino'verall height to completely dispense with the extra tube adjacentbalance tube 42 thus simplifying the manufacture of components 42 and44. To this end, as seen in FIG. 2, the conventional pressure regulatingvalfve structure is replaced with a spring 48 that is disposed entirelyin cover 32 and is substantially flush with the top surface thereof.Spring 48 is formed as a helical-coiled spring having longitudinalconvolutions with one end that is seated in sealing relation at 50directly to the cover and is carried completely by the cover 32. It ispossible to use a helical conventional spring, but a tapered spring ofthe type shown is preferred as will become apparent. In the manufactureof small tension springs it is extremely diicult to provide consistencyso that each spring coil will begin to stretch uniformly under a givenload and, as a result some turns or convolutions of the spring open andsome do not open. In an iron it is undesirable to allow a slow build-upin steam pressure because of the resulting slow spray start up. With theunique structure shown these normal drawbacks can be used to providemutual advantages by using a prestressed spring. By tightly -winding andprestressing the springy in a closed or unstretched position and heattreating the spring it is possible to prevent any stretching until adesired prestressed force is slightly exceede-d when the spring 'willsuddenly open. Thus, the consistency requirement is obviated and apressure build-up in the iron system for spray operation is provided. Byproper spring design then, the steam may be bled for steaming throughapertures 12.

During spraying, a large amount of steam is used, thus the amount thatis bled through regulating valve 46. is low while, during periods whenthe user is just steam ironing in normal position, the amount of bleedis identical to the amount produced. The regulating valve and spring arethus designed to bleed the steam from time to time to maintainsubstantially constant pressure in the system.

Referring to FIG. 5, the desired flow-pressure relationship isillustrated. In this figure, the pressure regulating valve bleeds athigh ow condition A while the iron is steaming and bleeds at low flowcondition B while the spray is being used. Consequently, as an example,it is desired to have an operating steam pressure range between 60-120inches of water. In such an iron, if operated continuously, the ironwould produce a maximum of around 45 surface cubic feet of steam perhour at 500 F. steam and .025 lb./min. steam rates. Thus, it is desiredto produce a curve of the type shown in FIG. 5 with a knee at B so thatno ow takes place and pressure builds up until the knee is reached andthe pressure regulator must then control the pressure in the notedrange. As indicated, it is extremely diflicult to provide consistenthelical springs in large quantities. A vertically disposed spring thatis coned or tapered in the downstream direction is preferred because, insuch a spring, it is possible to get a larger deflection in a shortervertical space whereby the spring can be sealed at its top portion andcarried in a small support eg. substantially entirely within the chambercover. Also, in tapered springs, the largest diameter free coil is thelirst to operate i.e. it dellects first in response to pressure. Thus,it is easier and more exact to design to a single coil than a pluralityso a tapered spring is preferred. It isy thus possible to reproduce thespring in quantity where, in eifect, only one coil need be designed. Inthe FIG. 2 modification, where steam dome 44 is shown closer because ofspace limitations, this first free coil is top coil 52 immediately belowseal S0. Consequently, the spring is prestressed in a closed orunstretched position and, as shown, is tapered in the downstreamdirection away from the tank. In order to open the spring, check valvemeans that, conveniently, may be in the form of ball check meansgenerally indicated at 53 is provided. Any check means acting inconjunction with the particular prestressed spring Will suice and a ballcheck is a straight forward solution. Similarly, several modificationsof ball check valves are suggested as will become apparent. It has beennoted that, on occasion, as when steam escapes with the iron in a heelrest position, there can occur a resonant condition of the spring thatmay result in a buzzing sound. This can be alleviated in a preferredform as shown in FIGS. l and 2 wherein ball 54 seats in the taperedportion of the spring and, in normal position, nests under a shapedinsert 55. The ball and insert thus rest against each other with theinsert being shaped to provide a relatively large rubbing surfaceagainst the spring to damp any vibrations. It has been found effectiveto make the insert a light Weight ceramic for the desired coeflicient offriction and low cost solution. A modification that uses two balls 56 asshown in FIG. 3, where dome 44 is moved in, may also be used but theformer is preferred. Similarly, a modification using a single ball l57as shown in FIG. 4 may be used. Both FIG. 3 and 4 versions operatesatisfactorily albeit with occasional buzzing which is eliminated in thepreferred form. The ball means may rest in the lower tapered portion ofthe spring on the bottom coil directly or through a seat member 58resting in the spring. Thus,

upon an increase in pressure in the generator, the check valve preventsor blocks flow to the soleplate and allows a pressure build-up until thepressure is equal to or greater than ambient plus the prestressed valueat which time the pressure on the check valve unstresses the spring tostretch it to suddenly open and bleed steam through the dischargepassage and through the spring convolutions to the steam distributingmeans downstream below the cover. When the pressure in the generator isequal to or lower than ambient, the check valve permits ready owupstream. This is important for venting the iron during emptying andwhen filling in the heel rest position where the spring 48 is thenhorizontally aligned so that ball means 53 rolls away from the seat. Theball of the ball means cannot completely roll out of position because ofa screen 59 of the FIGS. 1-2 and 4 modifications or a domed screen 60 ofthe FIG. 3 modification. The screen limits the movement of the checkmeans and also screens the steam. The screen may be fastenedsubstantially liush with the upper surface of the cover as shown bymeans such as a press lit or staking or overlapping ears or any othersuitable means to secure the screen in the coverplate.

The construction thus uses, as seen in FIG. 4, four or live simpleelements for regulating the pressure and these replace more than doublethe number of parts in conventional structure. Additionally, the entirepressure regulating valve is located substantially entirely in the cover32 to reduce the height of the valve. The extremely simple, reliablestructure is cheaper to manufacture and assemble resulting in a lowercost iron.

While there have been described preferred forms of the invention,obvious equivalent variations are possible in light of the aboveteachings. It is therefore to be understood that within the scope of theappended claims the invention may be practised, otherwise than asspecifically described, and the claims are intended to cover suchequivalent variations.

We claim:

1. In a steam-powered spray iron having a steam generator, a closedwater tank above said generator, means to pass water from said tank tosaid generator, means providing pressure communication between saidgenerator and tank, a steam discharge passage providing the sole outletfor steam from said generator during normal operation, the improvementin a pressure regulating valve in said passage for maintaining asubstantially uniform operating pressure in said generator and tank,said valve comprising:

a helical-coiled spring disposed in and sealed to said r passage,

said spring being prestressed in a closed unstretched position,

means cooperating with said spring and operative to permit flow throughsaid spring upstream toward said generator when pressure in saidgenerator is equal to or lower than ambient and to permit ow from saidgenerator downstream through said passage when generator pressure isequal to or greater than ambient plus the prestressed value, and

steam distributing means downstream of said valve and connected to saidpassage.

2. Apparatus as described in claim 1 wherein said spring is formed oflongitudinal convolutions and one end is sealed directly to saidpassage.

3. Apparatus as described in claim 2 wherein said spring is verticallydisposed in said passage and is seated in sealing relation at the topportion of said spring.

4. Apparatus as described in claim 3 having a screen member disposedover said top spring portion, and

means securing said screen thereover.

5. In a steam-powered spray iron having a steam generator, a closedwater tank above said generator and a chamber cover therebetween, meansto pass water through the cover from said tank to said generator, meansproviding pressure communication between said generator and tank, asteam discharge passage through said cover providing the sole outlet forsteam from said generator during normal operation, the improvement in apressure regulating valve in said passage for maintaining asubstantially uniform operating pressure in said generator and tank,said valve comprising;

a helical-coiled spring seated in sealing relation with and carried bysaid cover,

said spring being prestressed in a closed unstretched position and beingtapered in the downstream direction away from said tank,

check valve means disposed within said spring and operative to permitiiow through said spring upstream toward said generator when pressure insaid generator is equal to or lower than ambient and to block reverseow,

whereby said check valve unstresses said spring to stretch it and permitflow through the passage and spring convolutions downstream when saidgenerator pressure is equal to or greater than ambient plus theprestressed value, and

steam distributing means downstream below said cover and connected tosaid passage.

6. Apparatus as described in claim 5 wherein said spring is formed oflongitudinal convolutions and the upper end is sealed directly to saidcover.

7. Apparatus as described in claim 6 wherein said spring is verticallydisposed in said passage, and

said check valve is a ball check means seated in the lower taperedportion to unseat in heel rest position when said spring is horizontallyaligned.

8. Apparatus as described in claim 7 wherein a shaped insert rests onsaid ball check means and is formed to provide a rubbing surface againstsaid spring to dampen vibrations therein.

9. Apparatus as described in claim 8 having a screen member disposedover the top of said spring, and

means securing said screen thereover in said cover substantially flushwith the upper surface thereof.

References Cited UNITED STATES PATENTS 181,288 8/1876 Shaw 38-77.5X2,125,435 8/1938 Erling 3877.5X 3,041,757 7/1962 Swenson et al. 38-77.53,045,370 7/ 1962 Foster 38-77.5 3,403,556 10/ 1968 Koester 38-77.5X

PATRICK D. LAWSON, Primary Examiner

